The present invention relates generally to agricultural machinery and, more particularly, to a drum chopper with an improved cutting blade mounting arrangement.
In some agricultural machines, crop material is fed into a drum chopper where a cutter chops the material and then discharges it. The drum chopper includes a housing and a fixed horizontal axis. A cutter mechanism rotates about the horizontal axis and within the housing and includes several receptacles, which are arranged in groups of at least two and equidistant from one another around the outer circumference of the cutter mechanism. A blade, which has a shape similar to the cross-section of a bowl, is attached to each group of receptacles.
A system for mounting the blades to the receptacles is known from U.S. Pat. No. 3,126,931. In the described system, the receptacles have mounting surfaces intended to accept the curved back surfaces of the blades. The individual blades are provided with mounting holes passing entirely through the blades to allow the blades to be secured to the receptacles by bolts. This design contains multiple drawbacks. First, the mounting holes weaken the blades. Also, bolting the blades into a form-locking relationship with the receptacles introduces undefined stresses arise in the blades. Another disadvantage arises due to the adverse affect on the flow of chopped crop material by the bolt heads extending into the bowl of the blades. Furthermore, because the bolt heads are located near the cutting edges of the blades, they are subjected to increased wear by the stream of chopped crop material.
The present invention is directed to overcoming one or more of the problems set forth above.
An aspect of the invention is to provide an arrangement for mounting the blades to the receptacles such that the structural integrity of the blades is maintained and that additional stresses on the blades are minimized.
In accordance with another aspect of the invention, there is provided a drum chopper in which cutting blades are locked in a form-fitting relationship to blade receptacles. The form-fitting relationship between the receptacles and blades is secured by a locking structure between the mating surfaces of each receptacle and blade and a clamping piece. In one embodiment, the locking structure is integrally formed in the mating surfaces of the receptacle and blade by a latch projection in the receptacle and a lug in the blade. In another embodiment, the locking structure is formed by matching grooves in the mating surfaces of the receptacle and blade and a key inserted into the matching grooves. The clamping piece is inserted between the blade and a stop in the receptacle to secure the arrangement.
Other objects, aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings. These aspects are merely illustrative and nonlimiting examples with the possibility of numerous other aspects being present with this invention.